A new whey to deal with byproducts

Since the Greek yogurt fad began around 2011, Americans have consumed tons of the fermented milk product.

Literally.

In 2004, Greek yogurt made up one to two percent of the U.S. yogurt market; in 2015, that percentage increased to 36 percent. That same year, 2015, Americans ate about 771,000 metric tons of Greek yogurt.

Touted as higher in protein and calcium and lower in sugar and sodium than the regular, plebeian yogurt, this novel dairy product became, and still is, a tremendous success.

As a result of the ballooning Greek yogurt market, producers faced another increase: acid whey. This substance, generated by Greek yogurt production, is essentially the liquid byproduct left over after the yogurt has been strained to produce the trademark, thick and creamy texture of Greek yogurt. For every kilogram of Greek yogurt produced, two to three kilograms of acid whey are created.

“Things don’t just go away,” biology professor Dr. Jeff Ploegstra said. “Whenever we produce something, we have to think about where it goes and where the byproducts go.”

In the past, farmers used acid whey as fertilizer. This works when you are making a little over one hundred thousand tons of acid whey a year. When you are making 2.3 million tons of it, however, there is way too much to use on fields.

“In the past, we’ve assumed that the ecosystem can just take care of our waste,” said Ploegstra “but eventually we find that we’re adding waste at a higher rate than the ecosystem can cope with. The Greek yogurt industry is an example of this.”

In order to address this surplus, scientists and yogurt-makers sought alternative methods of using the Greek yogurt by-product. And they have been largely successful in their search: 75 percent of patents on acid whey usage have been published in the past five years.

Additionally, some companies have used bacteria to break down the whey into methane, a chemical that can be used to generate electricity. The whey-digesting system at a FAGE facility in New York, for example, uses whey to fuel three 350-kW generators, creating more energy than that facility can use. The company then sells this excess electricity to the power grid.

General Mills likewise pursued converting components of the acid whey into soluble fiber. That fiber could be added to cereals, fruit snacks, baked goods and other foods. Other companies are using acid whey as animal fodder or making it into industrial grade ethanol.

Across the nation, industries are seeking responsible uses for the whey by-product. Ideally, companies should be proactive, rather than reactive, with their response to waste products.

“We ignore things until they become a problem,” said Ploegstra. “It would be wise to anticipate the consequences of our actions rather than reacting to problems once we can’t ignore them anymore.

“Of course, this takes intellectual input. It takes work. But using a little bit of caution in our industries would be really smart. This is a valuable lesson both for industries and individuals.”